1. Technical Field
The present disclosure relates to occurrence of osteopontin in tissues and fluids of subjects afflicted with pleural mesothelioma, and discloses serum osteopontin levels in three populations: asbestos-exposed subjects without malignancy, unexposed subjects without malignancy, and asbestos-exposed subjects with pleural mesothelioma.
2. Related Art
Pleural mesothelioma is an asbestos-related malignancy with a median survival of 8-18 months (Martino D et al., Clin Lung Cancer 2004; 5(5):290-298). Retrospective studies of small numbers of pleural mesothelioma patients have attempted to define biomarkers that predate symptoms in a population at high risk for pleural mesothelioma. These markers include tissue polypeptide antigen, carcinoembryonic antigen, hyaluronic acid and ferritin, hyaluronic acid alone, cytokeratins including Cyfra 21™, CA-125, and mesothelin related protein (SMRP) (Ebert W, et al., Anticancer Res 1997; 17(4B):2875-2878; Pettersson T, et al. Chest 1988; 94(5):1037-1039; Frebourg T, et al. Cancer 1987; 59(12):2104-2107; Roboz J, et al. J Natl Cancer Inst 1989; 81(12):924-928; Chiu B, et al, Cancer 1984; 54(10):2195-2199; Boersma A, et al. Bull Physiopathol Respir (Nancy) 1980; 16(1):41-45; Hellstrom P E, et al. Scand J Respir Dis 1977; 58(2):97-102; Thylen A, et al. Cancer 2001; 92(5):1224-1230; Pluygers E, et al. Cancer Prev 1992; 1 (2):129-138; Lee Y C, et al. Aust N Z J Med 1999; 29(6):765-769; Paganuzzi M, et al. Chest 2001; 119(4):1138-1142; Schouwink H, et al. Lung Cancer 1999; 25(1):25-32; Marukawa M, et al. Acta Med Okayama 1998; 52(2); 119-123; Bonfrer J M, et al. Anticancer Res 1997; 17(4B):2971-2973; Almudevar B E, et al. Histopathology 1997; 31(3):267-273; Robinson B W, et al. Lancet 2003; 362(9396):1612-1616).
The lifetime risk for pleural mesothelioma in an asbestos-exposed population is 4.5-10%. Workers at risk for high exposure include miners, factory workers, carpenters, electricians, ship fitters, ship electricians, boilermakers, insulation manufacturers, railroad workers, gas mask manufacturers, and pipe insulators (Roggli V L, et al. Ultrastruct Pathol 2002; 26(2):55-65). It has been estimated that as many as 7,500,000 construction workers in the United States have used asbestos construction materials for fireproofing buildings, acoustic control, duct work and pipe and boiler instillation (Schottenfeld D, et al. Cancer Epidemiology and Prevention. Philadelphia: W.B. Saunders Co., 1982). Moreover, asbestos is still a hazard for an estimated 1.3 million workers in the construction industry in the United States and for workers involved in maintenance of building and equipment (U.S. Department of Labor OSaHA. Safety and Health Topics: Asbestos. 2003).
At present, there are no economically feasible, validated modalities to screen all these individuals potentially at risk when the estimated number of new cases of mesothelioma in the United States per year is only 2500-3000 (age adjusted incidence of 2/100,000) (Weill H, et al. Occup Environ Med 2004; 61(5):438-441). However, the incidence of mesothelioma is rising in and outside the United States, including Canada and Australia. Median survival in pleural mesothelioma is 9-12 months from diagnosis; in advanced cases, resection of the tumor can prolong survival for about three months. Patients with, stage IA disease, however, can survive 5 or more years if the tumor is promptly resected. Unfortunately, the difficulty in detecting early disease means that less than 5% of patients with pleural mesothelioma present in stage IA; in fact 85% of patients first present once they are exhibiting symptoms of the disease. Hence, a marker or series of biomarkers that can predict the development of mesothelioma or detect pleural mesothelioma in its early stages in asbestos-exposed populations would be of considerable value.